Data Transmission Method, and Related Device and System

1. A data transmission method, the method comprising: receiving, by a first base station, a first message sent by a second base station, wherein the first message is used to indicate that the second base station needs to transmit data; assigning, by the first base station, at least one address to the data that need to be transmitted by the second base station, wherein the at least one address includes an address corresponding to the first base station that is used to identify data transmission through an interface between the first base station and the second base station; and sending, by the first base station, a second message to the second base station, wherein the second message carries the at least one address, and the at least one address is used by the first base station to identify the data of the second base station, and wherein the data that needs to be transmitted is uplink data that needs to be transmitted to a core network and the second base station is a serving base station to which a user terminal (UE) in a radio resource control (RRC) inactive state is moved from an anchor base station that is the first base station, or wherein the data that need to be transmitted is downlink data that needs to be transmitted to the UE and the first base station is the serving base station and the second base station is the anchor base station, and wherein the first message carries an expected quantity of addresses, and an assigned quantity of the at least one address in the second message is the same as the expected quantity of addresses in the first message.

2. The method according to claim 1 , wherein the first message carries at least one identifier of a first transmission granularity, and a mapping relationship between the identifier of the first transmission granularity and an identifier of a second transmission granularity; and the identifier of the first transmission granularity is used to identify the data that corresponds to the identifier of the first transmission granularity and that needs to be sent by the second base station to the first base station; and wherein before the sending, by the first base station, the second message to the second base station, the method further comprises: determining, by the first base station, at least one identifier of the second transmission granularity based on the at least one identifier of the first transmission granularity and the mapping relationship between the identifier of the first transmission granularity and the identifier of the second transmission granularity; and assigning, by the first base station, a corresponding address to each of the at least one identifier of the second transmission granularity, wherein the second message further carries the identifier that is of the second transmission granularity and that corresponds to each of the at least one address, wherein each of the first transmission granularity and the second transmission granularity is a quality of service (QoS) flow, a protocol data unit (PDU) session, or a data radio bearer (DRB).

3. The method according to claim 1 , wherein the first message carries at least one identifier of a second transmission granularity, and the identifier of the second transmission granularity is used to identify the data that corresponds to the identifier of the second transmission granularity and that needs to be sent by the second base station to the first base station; and before the sending, by the first base station, the second message to the second base station, the method further comprises: assigning, by the first base station, a corresponding address to each of the at least one identifier of the second transmission granularity, wherein the second message carries the identifier that is of the second transmission granularity and that corresponds to each of the at least one address, and wherein a quantity of the at least one identifier of the second transmission granularity is the same as the assigned a quantity of the at least one address.

4. The method according to claim 1 , wherein the method further comprises: receiving, by the first base station, a third message sent by the second base station, wherein the third message carries an identifier that is of a second transmission granularity and that corresponds to each of the at least one address.

5. The method according to claim 2 , wherein the first transmission granularity or the second transmission granularity comprises any one of the following: a quality of service QoS flow, a protocol data unit PDU session, and a data radio bearer DRB.

6. A data transmission method, the method comprising: sending, by a second base station, a first message to a first base station, wherein the first message is used to indicate that the second base station needs to transmit data; and receiving a second message sent by the first base station, wherein the second message carries at least one address that has been assigned by the first station to the data that need to be transmitted by the second station, wherein the at least one address includes an address corresponding to the first base station that is used to identify data transmission through an interface between the first base station and the second base station and that is used by the first base station to identify the data of the second base station, and wherein the data that needs to be transmitted is uplink data that needs to be transmitted to a core network and the second base station is a serving base station to which a user terminal (UE) in a radio resource control (RRC) inactive state is moved from an anchor base station that is the first base station, or wherein the data that need to be transmitted is downlink data that needs to be transmitted to the UE and the first base station is the serving base station and the second base station is the anchor base station, and wherein the first message carries an expected quantity of addresses, and an assigned quantity of the at least one address in the second message is the same as the expected quantity of addresses in the first message.

7. The method according to claim 6 , wherein the first message carries at least one identifier of a first transmission granularity, and a mapping relationship between the identifier of the first transmission granularity and an identifier of a second transmission granularity; and the identifier of the first transmission granularity is used to identify the data that corresponds to the identifier of the first transmission granularity and that needs to be sent by the second base station to the first base station; and wherein the second message carries the identifier that is of the second transmission granularity and that corresponds to each of the at least one address, and the assigned quantity of the at least one address in the second message is the same as a quantity of the at least one identifier of the first transmission granularity in the first message, wherein the at least one identifier of the second transmission granularity is determined based on the at least one identifier of the first transmission granularity and the mapping relationship between the identifier of the first transmission granularity and the identifier of the second transmission granularity, wherein each of the first transmission granularity and the second transmission granularity is a quality of service (QoS) flow, a protocol data unit (PDU) session, or a data radio bearer (DRB).

8. The method according to claim 6 , wherein the first message carries at least one identifier of a first transmission granularity, and a mapping relationship between the identifier of the first transmission granularity and an identifier of a second transmission granularity; and the identifier of the first transmission granularity is used to identify the data that corresponds to the identifier of the first transmission granularity and that needs to be sent by the second base station to the first base station; and wherein the second message carries the identifier that is of the second transmission granularity and that corresponds to each of the at least one address, and the assigned quantity of the at least one address in the second message is the same as a quantity of the at least one identifier of the second transmission granularity in the first message.

9. The method according to claim 6 , wherein the second base station has data that corresponds to the at least one identifier of the second transmission granularity and that needs to be transmitted to the first base station, and wherein the method further comprises: assigning, by the second base station, the corresponding identifier of the second transmission granularity to each of the at least one address, wherein different addresses correspond to different identifiers of the second transmission granularity; and sending, by the second base station, a third message to the first base station, wherein the third message carries the identifier that is of the second transmission granularity and that corresponds to each of the at least one address.

10. A first base station comprising: a communications unit; and a processor coupled to the communication unit that is configured to receive a first message sent by a second base station, wherein the first message is used to indicate that the second base station needs to transmit data; wherein the processor coupled to the communications unit is configured to assign at least one address to the data that need to be transmitted by the second base station, wherein the at least one address includes an address corresponding to the first base station that is used to identify data transmission through an interface between the first base station and the second base station; and wherein the processor coupled to the communications unit is configured to send a second message to the second base station, wherein the second message carries the at least one address, and the at least one address is used by the first base station to identify the data of the second base station, and wherein the data that needs to be transmitted is uplink data that needs to be transmitted to a core network and the second base station is a serving base station to which a user terminal (UE) in a radio resource control (RRC) inactive state is moved from an anchor base station that is the first base station, or wherein the data that need to be transmitted is downlink data that needs to be transmitted to the UE and the first base station is the serving base station and the second base station is the anchor base station, and wherein the first message carries an expected quantity of addresses, and an assigned quantity of the at least one address in the second message is the same as the expected quantity of addresses in the first message.

11. The first base station according to claim 10 , wherein the first message carries at least one identifier of a first transmission granularity and a mapping relationship between the identifier of the first transmission granularity and an identifier of a second transmission granularity; wherein the identifier of the first transmission granularity is used to identify the data that corresponds to the identifier of the first transmission granularity and that needs to be sent by the second base station to the first base station; and before that the communications unit is configured to send the second message to the second base station, wherein the processor is configured to determine at least one identifier of a second transmission granularity based on the at least one identifier of the first transmission granularity and the mapping relationship between the identifier of the first transmission granularity and the identifier of the second transmission granularity; and the processor is further configured to assign a corresponding address to each of the at least one identifier of the second transmission granularity, and the second message further carries the identifier that is of the second transmission granularity and that corresponds to each of the at least one address, wherein each of the first transmission granularity and the second transmission granularity is a quality of service (QoS) flow, a protocol data unit (PDU) session, or a data radio bearer (DRB).

12. The first base station according to claim 10 , wherein the first message carries at least one identifier of a second transmission granularity, and the identifier of the second transmission granularity is used to identify the data that corresponds to the identifier of the second transmission granularity and that needs to be sent by the second base station to the first base station; and before that the communications unit is configured to send the second message to the second base station, the processor is configured to assign a corresponding address to each of the at least one identifier of the second transmission granularity, the second message further carries the identifier that is of the second transmission granularity and that corresponds to each of the at least one address, and a quantity of the at least one identifier of the second transmission granularity is the same as the assigned quantity of the at least one address.

13. The first base station according to claim 10 , wherein the communications unit is further configured to receive a third message sent by the second base station, wherein the third message carries an identifier that is of a second transmission granularity and that corresponds to each of the at least one address.

14. A second base station comprising: a communications unit; and a processor coupled to the communications unit that is configured to send a first message to a first base station, wherein the first message is used to indicate that the second base station needs to transmit data; and wherein the communications unit is configured to receive a second message sent by the first base station, wherein the second message carries at least one address that has been assigned by the first station to the data that need to be transmitted by the second station, wherein the at least one address includes an address corresponding to the first base station that is used to identify data transmission through an interface between the first base station and the second base station and that is used by the first base station to identify the data of the second base station, and wherein the data that needs to be transmitted is uplink data that needs to be transmitted to a core network and the second base station is a serving base station to which a user terminal (UE) in a radio resource control (RRC) inactive state is moved from an anchor base station that is the first base station, or wherein the data that need to be transmitted is downlink data that needs to be transmitted to the UE and the first base station is the serving base station and the second base station is the anchor base station, and wherein the first message carries an expected quantity of addresses, and an assigned quantity of the at least one address in the second message is the same as the expected quantity of addresses in the first message.

15. The second base station according to claim 14 , wherein the second base station has data that corresponds to at least one identifier of a second transmission granularity and that needs to be transmitted to the first base station; wherein the processor is configured to assign a corresponding identifier of the second transmission granularity to each of the at least one address, and different addresses correspond to different identifiers of the second transmission granularity; and wherein the communications unit is configured to send a third message to the first base station, wherein the third message carries the identifier that is of the second transmission granularity and that corresponds to each of the at least one address, wherein the second transmission granularity is a quality of service (QoS) flow, a protocol data unit (PDU) session, or a data radio bearer (DRB).